DESCRIPTION:(adapted from applicant's abstract) It is estimated that more than 2 million Americans suffer from a variety of chemosensory disorders, including impairments of gustatory function. These impairments significantly detract from the quality of life and increase exposure to health-related risks. Accordingly, the development of animal models, in which the gustatory system can be experimentally manipulated, is essential to gain an understanding of the underlying neurobiology of normal and abnormal taste function. The psychophysical assessment of sensation and perception in any nonhuman animal is challenging, but an absolutely necessary component to the overall analytical strategy aimed at understanding the neurobiology of sensory function. Over the last 2 decades, several inbred strains of mice have been identified as expressing phenotypes that differ from each other with respect to the ingestion of prototypical taste compounds, including sugars, alkaloids and salts. In some cases, congenic lines have been derived from these progenitor strains. In addition, taste-related targeted gene deletion and insertion preparations in mice have begun to appear. With only a few notable exceptions, all of these behavioral phenotypes have been identified through the use of interpretively limited long-term intake tests. The specific aims of the proposed research are: 1) to adapt current psychophysical procedures that have successfully been used to assess taste function in rats for use with mice, 2) to psychophysically test the hypothesis that significant differences in the intake of prototypical taste compounds between selected inbred strains of mice are attributable to gustatory processes, and 3) to determine which dimensions of gustatory function differ among selected inbred strains of mice. Using a theoretically relevant array of prototypical taste compounds, the PI will test mice for their affective responsiveness, threshold sensitivity, and discriminative capacity. Given: a) the wide availability of inbred strains suspected of possessing differing phenotypes in taste responsiveness, b) the rapid developmental pace of molecular techniques to discern and selectively manipulate the mouse genome, and c) the emergence of the trans-NIH mouse genome initiative, the proposed research is timely and important, and will likely facilitate advances in our understanding of the neurobiological basis of gustatory function.